The goals of this study are to determine if simultaneous bilateral subthalamic nucleus stimulation or simultaneous bilateral globus pallidus stimulation is more effective in reducing symptoms of Parkinson's disease, and if deep brain stimulation or best medical therapy is more effective in improving Parkinson's disease symptoms

The Difference of Time Spent in the 'on' State Without Troublesome Dyskinesia Based on Patient Motor Diaries as Compared to the Baseline. [ Time Frame: at six months ] [ Designated as safety issue: No ]

Secondary Outcome Measures:

The Change of Scores on the UPDRS for Blinded Assessed Motor Function 'Off' Medication and 'on' Stimulation [ Time Frame: at six months ] [ Designated as safety issue: No ]

Unified Parkinson's Disease Rating Scale (UPDRS Part III) measured while the patient is off medications and on stimulation at follow-up visits post surgery. UPDRS Part III has 14 items assessing motor skills including facial expression and speech, tremors, rigidity, posture, gait, and bradykinesia. Left and right sides (arms, legs, and hands) are assessed separately for seven of the functions. A summary score ranging from 0 to 108 is generated by adding the 14 specific motor function responses. The motor function (UPDRS part III) assessments are done by turning on the stimulation with and without taking PD medications (on/off) at each in-person visit. The higher score indicates that the condition is worse.

The DBS site (STN or GPi) will be assigned on a random basis at the time the patient enters the surgical phase of the trial.

Active Comparator: 2

Best Medical Therapy

Other: best medical therapy

Participants will initially be randomized to DBS or to 6 months of "best medical therapy." BMT participants will then proceed into the surgical phase of the trial. Effective 08/05/05, randomization to the BMT arm has been discontinued since the study has sufficient information to compare the outcomes of DBS and BMT patients at 6 months.

Detailed Description:

Deep Brain Stimulation (DBS) is a promising therapy for Parkinson's disease (PD). Whether DBS is superior to comprehensive best medical therapy or whether some patients or symptoms respond better to DBS in one area of the brain or the other is currently not known. The goals of this project are to compare the effectiveness of DBS and comprehensive medical therapy as treatments for PD, and to compare bilateral DBS at 2 areas of the brain--the subthalamic nucleus (STN) and the globus pallidus (Gpi)--to determine the most effective brain site for surgical intervention In this prospective, randomized, multi-center trial, 316 patients will be enrolled at 13 centers over four and a half years. Patients will initially be randomized to immediate surgery (DBS) or to 6 months of "best medical therapy." BMT patients will then proceed into the surgical phase of the trial. The DBS site (STN or GPi) will be assigned on a random basis at the time the patient enters the surgical phase of the trial. Patients will be followed for two years post surgery (24-30 months). Effective 08/05/05, randomization to the BMT arm has been discontinued since the study has sufficient information to compare the outcomes of DBS and BMT patients at 6 months. The findings will be critically important in establishing the optimal surgical treatment of the disabling symptoms of PD.

available and willing to be followed-up according to study protocol, and

no intracranial abnormalities that would contraindicate surgery (based on pre-operative magnetic resonance imaging of the brain).

Exclusion Criteria:

"Parkinson's plus" syndromes,

medical contraindications to surgery or stimulation,

active alcohol or drug abuse,

score on minimental status exam 24 or lower, or other neuropsychological dysfunction (e.g., dementia) that would contraindicate surgery,

concurrent participation in another research protocol.

Contacts and Locations

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Please refer to this study by its ClinicalTrials.gov identifier: NCT00056563